Envelope



atented Sept. 7, 1937 FFICE acorn application Juny c, rese, sensi No.88,992

il Claims.

This invention relates to envelopes and similar containers particularlyto those employing rubber gum solutions, known as latex, for eiectingseal thereof. Envelopes of this character have a gummed area on thesealing flap adapted to register with a similar gummed area on thebottom of the envelope on the ap that is folded there# over and adaptedto adhere or coalesce with each other responsive to slight pressureapplied to the overlapped areas. Such seals are very effective anddesirable in that they do not require the use of moisture in edecting aseal, however,v the latex gum is readily soluble in certain solvents sothat the envelope may be readily opened by unauthorized persons andresealed without leaving sumcient telltale marks to show that theenvelope has been tampered with.

It is, therefore, the principal object of the present invention toprovide an envelope or container of this character with means fordisclosing whether or not the seal has Ibeen tampered with after theseal has been eiected.

In accomplishing this and other objects of the invention, as hereinafterpointed out. I have provided improved details of structure, thepreferred form of which is illustrated in the accompanying drawing,wherein:

Fig. l is a perspective view of an envelope equipped with sealing areasembodying the features of the present invention and showing the sealingflap in opened position.

Fig. 2 is a similar view showing the sealing ap in closed position.

Fig. 3 is a perspective view similar to Fig. 1 showing the color changein the sealing areas after the envelope has been opened with the ald ofa solvent.

Fig. 4 is a section through the envelope on the line t-- of Fig. 3.

Referring more in detail to the drawing:

l designates a type of envelope employing latex seals and which includesa blank folded to provide front and back portions 2 3, side flaps @-5and a sealing flap 6, the back portion 3 being sealed to the side aps iland 5 as in conventional envelope construction. The seals between theback portionl and side aps, however, terminate short of the upper edge 1to provide a supplemental ap t that is adapted to be folded back againstthe outer face of the portion 3 on a score line 9 so that the gum lilthereon may be folded against the bodv portion oi the envelope toprevent adhesion of the gum area Il on the 5' sealing flap when thesealing nap is folded on its (Cil. 229-83) score l2, aswhen packagingthe envelopes prior to use.

When the envelope is to be sealed the supplementary ap B is turned backto expose the gum area l@ which then registers with the correspondinggum area ll on the sealing flap when the sealing ap is folded thereoverto close the envelope. Then when slight pressure is applied to theoverlapped areas, the gums coalesce to produce a seal Without the use ofmoisture. When ordinary latex solutions are used, the gum mayY bedissolved by various rubber solvents and the envelope opened, afterwhich it may be resealed without any indication that it has been opened.

The envelope as thus far described is of conventional construction andspecifically forms no part of the present invention.

As above pointed out, it is the purpose of the present invention toprovide means whereby any tampering with the seal is readilydistinguishable. In carrying out this object I, therefore employ latexsolutions which are distinguishably aiected by rubber solvents. Forexample, one form of the invention consists in employing a latex gum onone of the areas which has a distinguishing characteristic from thelatex gum on the other area, that is the gum area on the sealing flapmay be coated with a gum of one color while that on the other flap 8 maybe coated with a gum of diierent color so that in case an attempt ismade to dissolve the gums, the colors become mixed or blended by thesolvent to produce a third color thereby indicating that the envelopehas been opened.

In carrying out this form of the invention, I preferably color the gumsolutions with primary coloring matter that is readily mixed therewithto produce red. blue and yellow gum solutions. In the illustratedinstance, the gummed areas on the aps and 8 are lined to indicate gumsolutions of red and blue colors respectively which, when sealed, willshow a definite line of division between the colors, however, should anattempt be made to dissolve the' gums, the solvent being misclble withthe gums, will cause the mixing and blending of the gums to produce apurple color, thereby indicating that the envelope has been opened withthe aid of a solvent after it has been initially sealed.

Latex solutions of other colors may be em- V ployed, such as red andyellow which will produce an orange when the colors become mixed bymeans of a solvent, or blue and yellow which will produce a green. Whilebasic or primary colors are preferable, other colors may be usedproviding they produce a blend or mixture when reaed upon by a solvent.f

Attention is here directed to the fact that should the sealing areas berecoated with gum solutions of the original colors, there is sumcientabsorption of the resulting color in the fibers of the paper to giveevidence that the envelope has been opened.

From the foregoing, it is obvious that E have provided an envelope orsimilar container which may be equipped with latex seals that will giveindication that the envelope has been tampered with in case an attemptis made to open it by means of a solvent.

What I claim and desire to secure by Letters Patent is:

l. A container provided with interengageable sealing areas respectivelycoated with latex. gums of different color whereby said colored gums areblended to produce a different color when the gums are acted upon by asolvent.

2. A container provided with corresponding sealing areas respectivelycoated with latex gums of dierent primary colors whereby said gums acca,ma

are blended to produce a different shade when acted upon by a solvent.

3. An envelope including a body portion having a sealing area providedwith latex gum of one color. and a sealing ap on the body portion havinge, sealing area provided with latex gum of a different color that isadapted to coalesce with the rst mentioned gum when the sealing ap isfolded over the body portion to bring said sealing areas into registry,said latex gums being miscible whenacted upon by a solvent to form acolor different than the original colors of the latex gums.

4. An envelope including a body portion havingl a sealing area providedwith a. latex gum of primary color, and a. sealing ilap on the bodyportion having a sealing area provided with latex gum oi a. differentprimary color that is adapted to coalesce'with the rst mentioned gumwhen the sealing flap is folded over the body portion to bring saidsealing areas into registry, said latex gums being miscible when actedupon by a solvent to form a 'secondary color.

WALTER J. BERKOWITZ.

